PSCM

DTC C0900 (PSCM)

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC C0900
- Device Voltage High

Circuit/System Description

The power steering control module (PSCM) has a discrete battery voltage supply circuit. The PSCM monitors the voltage level on this circuit to protect itself against high voltage damage.

Conditions for Running the DTC

Ignition is ON.

Conditions for Setting the DTC

Power steering system voltage is greater than 16 volts for at least 1 second.

Action Taken When the DTC Sets

* DTC C0900 00 is stored in memory.
* The DIC displays the POWER STEERING warning message.
* The PSCM is disabled to protect itself.
* No steering assist is provided.

Conditions for Clearing the DTC

* A current DTC will clear when the power steering system voltage returns to less than 16 volts.
* A history DTC will clear after 100 consecutive ignition cycles from when power steering system voltage is less than 16 volts.

Diagnostic Aids

Jump starting the vehicle, or turning ON the ignition while charging the vehicles battery can cause DTC C0900 00 to set.

Circuit/System Verification

1. If the DTC is history, refer to Charging System Test. Charging System Test
2. Start the engine, record the voltage at the battery terminals. Observe the scan tool Battery Voltage Signal parameter in the PSCM data list. Voltages should not differ by more than 1 volt.

• If more than 1 volt, replace the PSCM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests

Control Module References for PSCM replacement, setup and programming.